Air duct assembly for rotor, associated rotor and electric machine

Abstract

An air duct assembly for a rotor of an electric machine and associated rotor and electric machine. The air duct assembly includes a base plate arranged between core laminations of the rotor, where the base plate has ventilation holes axially aligned with inlet channels of the rotor respectively; and a plurality of airflow guides axially protruding from a radial outer portion of an end surface of the base plate relative to the ventilation hole. The plurality of airflow guides includes a plurality of first guiding members extending radially; and a plurality of second guiding members arranged between the first guiding member and the ventilation holes and radially spaced apart from the first guiding member by a predetermined distance.

1 . An air duct assembly for a rotor of an electric machine, comprising:
 a base plate arranged between core laminations of the rotor and comprising ventilation holes axially aligned with inlet channels of the rotor respectively; and   a plurality of airflow guides axially protruding from a radial outer portion of an end surface of the base plate relative to the ventilation hole, the plurality of airflow guides comprising:
 a plurality of first guiding members extending radially; and 
 a plurality of second guiding members arranged between the first guiding member and the ventilation holes and radially spaced apart from the first guiding member by a predetermined distance. 
   
     
     
         2 . The air duct assembly of  claim 1 , wherein the plurality of second guiding members are tilted, with respect to the corresponding first guiding members, at a predetermined angle in a rotating direction of the rotor radially outside to inside. 
     
     
         3 . The air duct assembly of  claim 2 , wherein the predetermined angle is in a range of 25°-60°. 
     
     
         4 . The air duct assembly of  claim 1 , wherein a number of the second guiding members is less than a number of the first guiding members. 
     
     
         5 . The air duct assembly of  claim 4 , wherein the number of the second guiding members is half of the number of the first guiding members. 
     
     
         6 . The air duct assembly of  claim 1 , wherein the base plate further comprises:
 a plurality of fins aligned to fins of the core laminations, and   wherein the plurality of first guiding members are arranged on the plurality of fins respectively, and the plurality of second guiding members are arranged between the plurality of fins and the ventilation hole.   
     
     
         7 . The air duct assembly of  claim 5 , wherein the plurality of first guiding members radially extend a predetermined length on the fins, and the predetermined length is above a half of a radial length of the fin. 
     
     
         8 . The air duct assembly of  claim 1 , wherein the plurality of airflow guides are formed on the base plate by welding. 
     
     
         9 . The air duct assembly of  claim 1 , further comprising:
 a plurality of secondary airflow guides arranged between the ventilation holes and each extending radially.   
     
     
         10 . A rotor comprising at least one air duct assembly of  claim 1 . 
     
     
         11 . An electric machine comprising a rotor of  claim 9 . 
     
     
         12 . The rotor of  claim 10 , wherein the plurality of second guiding members are tilted, with respect to the corresponding first guiding members, at a predetermined angle in a rotating direction of the rotor radially outside to inside. 
     
     
         13 . The rotor of  claim 12 , wherein the predetermined angle is in a range of 25°-60°. 
     
     
         14 . The rotor of  claim 10 , wherein a number of the second guiding members is less than a number of the first guiding members. 
     
     
         15 . The rotor of  claim 14 , wherein the number of the second guiding members is half of the number of the first guiding members. 
     
     
         16 . The rotor of  claim 15 , wherein the plurality of first guiding members radially extend a predetermined length on the fins, and the predetermined length is above a half of a radial length of the fin. 
     
     
         17 . The rotor of  claim 10 , wherein the base plate further comprises:
 a plurality of fins aligned to fins of the core laminations, and   wherein the plurality of first guiding members are arranged on the plurality of fins respectively, and the plurality of second guiding members are arranged between the plurality of fins and the ventilation hole.   
     
     
         18 . The rotor of  claim 10 , wherein the plurality of airflow guides are formed on the base plate by welding. 
     
     
         19 . The rotor of  claim 10 , wherein the air duct assembly further comprises:
 a plurality of secondary airflow guides arranged between the ventilation holes and each extending radially.